Open AccessSelective harmonic mitigation‐pulse‐width modulation technique with variable DC‐link voltages in single and three‐phase cascaded H‐bridge inverters
Author(s) -
Moeini Amirhossein,
ImanEini Hossein,
Bakhshizadeh Mohamadkazem
Publication year - 2014
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2013.0315
Subject(s) - pulse width modulation , single phase , h bridge , voltage , link (geometry) , modulation (music) , harmonic , physics , control theory (sociology) , total harmonic distortion , topology (electrical circuits) , materials science , engineering , computer science , electrical engineering , acoustics , control (management) , artificial intelligence , computer network
There are different modulation techniques that can be used in medium‐voltage and high‐power electronic converters, but a few of them provide high efficiency and satisfy power quality requirements. This study presents a modified selective harmonic mitigation pulse‐width modulation (SHM‐PWM) technique which employs variable DC‐link voltages as a degree of freedom in cascaded H‐bridge (CHB) inverters. This degree of freedom increases the range of acceptable modulation indices, reduces the number of switching transitions and increases the number of harmonics that can be removed in selective harmonic elimination (SHE) (or SHM) techniques. Hence, in addition to efficiency improvement, a huge number of harmonics can be mitigated in AC side of the converter. Using this approach, triplen harmonics can be restricted to standard limits, in single‐phase inverters. In addition, the proposed SHM‐PWM approach employs the least number of switching transitions in a fundamental period to limit the specific number of harmonics compared to the alternative SHE or SHM techniques. In this study, the requirements of two well‐known grid codes EN 50160 and CIGRE WG 36‐05 are well satisfied and the validity of proposed method is verified by several simulations and experiments on a seven‐level CHB inverter in single‐phase and three‐phase operating modes.